Yes, color does affect plant growth. Colors
are simply different wavelengths of light that are
reflected by objects back. For example, plants
look green because they have a lot of chloroplast
in them, which absorbs all visible wavelengths of
light except green, so leaves look green to
us.

Different colors are associated with
encouraging different parts of plants to grow.
Blue light will allow the plant to grow leaves and
other vegetation and red light with blue allows
the plant to grow flowers. The plant does not
absorb the green light so does not use it to grow.

Answer 2:

The color or wavelength of light does affect
photosynthesis, which is how plants can basically
create their own food.Essentially, the reason why
plants are green is they are absorbing the other
wavelengths of light but reflecting back the
green. The wikipedia page on photosynthesis
goes into a lot more detail. Here is a short
page about the different absorption spectra of
light for different pigments in plants. .

Answer 3:

One of the professors at UCSB told his little
sister to do a science fair project, growing
plants under different colors of cellophane
sheets. Different colors of light came through
the cellophane sheets of different colors, onto
the plants. She won a prize for her project.

Answer 4:

Plants do respond differently to different
colors of light being shone on them, because
chlorophyll reflects green light and absorbs blue
and red (therefore, blue and red are useful for
photosynthesis, but green isn't).